Furnace-top down-comer and explosion-pipe.



Na. 704,556. Patented July l5, I902. P. MEEHAN. FURNACE TOP DOWN-OONERAND EXPLOSION PIPE.

(Application filed Nov. 13, 1901.)

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Patented July I5, I902.

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P. MEEHAN.

(Application filed Nov. 13. 1901.)

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"ma uunms PETERS ca, PuoTaumu. wAsmncYon. 0v 0 ITEDO STATES PATRICKMEEHAN, OF LOWELLVILLE, OHIO.

FURNACE-TOP DOWN-COMER AND EXPLOSION-PIPE.

SPECIFICATION formingpart of Letters Patent No. 704,556, dated July 15,1902.

Application filed November 13,1901. Serial No. 82,131. (No model.)

T0 at whom it may concern.-

Be it known that I, PATRICK MEEHAN, a resident of Lowellville, in thecounty of Mahoning and State of Oh'io, have invented a new and usefulImprovement in Furnace-Top Down-Corners and Explosion-Valves; and I dohereby declare the following to be a full, clear, and exactdescriptionthereof.

My invention relates to blast-turn aces, and more especially the topsthereof; and its object is to provide a construction of blast-furnacetop and down-comer whereby the amount of fine ores, coke, &c., carriedout by the gases is very greatly reduced and whereby most of that whichis carried out will be returned to the stack.

A further object of my invention is to provide a construction offurnace-top whereby liability of damage due to explosions is reduced.

Heretofore in blast-f u rnaces it has been the practice to place thegas-outlet ports in the upper portion ofthe masonry walls of the stackand to connect to the same the downcomer, which down-comer makes a bendjust outside the furnace-walls and then takes a downward direction andleads to the dustoollectors. Usually an explosion-valve is located atthe bend in the down-comer. In this construction the gas-port is locatedbut a short distance above the stock-line in the stack and the pointwhere the down-comer begins its downward course is not at all, or only ashort distance, above the gas-port, so that fine ores, coke, and thelike pass out with the gases in very large quantities. In fact, withlarge-sized modern blast-furnaces as much as one hundred tons per day offine ores and coke are carried over. Not only is the ore and coke thuscarried over wasted, but it must be removed at a considerableexpense,and it also gets into the hot-blast stoves, boilers, and otherparts of the machinery, causing serious damage and inconvenience.Furthermore, the explosion-valves in old f urnace constructions areconnected with the furnace chamber by rather crooked or tortuouspassages, and in the event of an explosion in the furnace-chamber thegases do not have a free and unobstructed passage to theexplosion-valves, so that great pressure is brought on the furnace-top,hopper, and

bell, thereby frequently seriously damaging the same.

The object of my invention is to overcome the above difiiculties anddefects and to provide such a construction of furnace-top that the fineores and coke which are carried up by the gases will be mostly returnedto the stack and also so that the exploding gases will find a free andunobstructed passage to the explosion-valves. To this end I provide thestack with the usual gas-ports, but leading in an upwardly inclineddirection, and preferably extend the same out through the top of themasonry walls. The down-comer is extended from the gas-port in asubstantially straight vertical direction to a considerable distanceabove the furnace-top and then makes an abrupt bend downward, so thatthe fine ores and coke suspended in the gases will have time to settleand most of it will fall back into the furnace-chamber, while that whichpasses over will fall down thedowntake,andthuspreventclo'ggingthedowncomer. Ats'ome point in thedown-comer at a considerable distance above the furnacetop andpreferably at the bend the same is enlarged, so as to form anexpansion-chamber in which the gases can expand to facilitate thedepositing or settling of the fine ores and coke, and I have connectedto such expansionchamber a pipe or fine leading back to the stack and bywhich the fine ores and coke which settle in the "expansion chamber arereturned to the furnace. I also place the explosion-valve at the upperend of the rising portion of the down-comer, so that a straightunobstructed passage is provided from the furnace-chamber to theexplosion-valve, and in event of an explosion the gases will not onlyhave a free unobstructed passage to the explosion-valve, but will alsoexpand and lose their force to a considerable extent in the enlargedspace provided by the downcomer, thereby saving to a great extent thebell, hopper, and top from injury.

My invention also comprises, in connection with the down-comer and pipefor returning the fine ores and coke to the furnace, a baffleplate insaid expansion-chamber, which will arrest the flow of the fine ores orcoke and cause the same to drop into the return dust= pipe.

I My invention also comprises the use of certain blast apparatus inconnection with such baffle-plate. l

My invention also comprises the use of a thimble extending through thewalls of the stack and forming the gas-port,which thimble is preferablywater-cooled and suitably supported by brackets in the masonry of theshaft and in turn serves to support the hopper-ring.

In the accompanying drawings, Figure 1 is a transverse vertical sectionthrough the up per part of the furnace, showing my improvement appliedthereto. Fig. 2 -is a vertical section on the line 2 2, Fig. 1. Fig. 3is a horizontal section on the line3 3, Fig. 1; and Figs. 4 and 5 aretransverse vertical sections showing modifications.

In the drawings, 1 represents the usual stack, which preferably has ametal shell 2, surrounding the masonry 3.

4 is the hopper-ring, which may be of the usual construction, and itsupports at its lower end the hopper 5.

6 is the usual bell. Y

The gas-port is shown at 7, and it is formed in Figs. 1 to 4 by means ofa cast-iron thimble 8. This thimble is suitably embedded in the masonryof the stack, and it may extend out through the side of the stack on anincline, as shown in Fig. 4,0r extend upwardly through the same, asshown in Fig. 1. When arranged as in Fig. 1, it is preferably providedwith shoulders which rest upon brackets 9, secured to the metal shell 2and embedded in the masonry 3, and said thimble is also provided withshoulders or flanges 10, upon which rests the flange of the hopper-ring4.

' This cast-metal thimble extends to the inner face. of the masonry walland prevents the latter from being cut out by the ores and dust and alsoprevents the cracking away of the masonry around the gas-port due to thegreat heat. Much inconvenience and annoyance exists in old furnaceconstructions due to the masonry around the gas-ports being cut out bythe ores and dust and cracking away by the heat to such an extent as togreatly weaken the top of the stack and necessitating frequent repairs.The thimble shown and described prevents this, and thus overcomes asource of serious annoyance. The lower flange of the thimble ispreferably thickened, as at 11, and cored out, as at 12, to form apassage through which water will be caused to circulate, the water beingsupplied in any convenient way, as by the inlet and outlet pipes 13 and14. This will cool the inner end of the thimble and prevent its burningout, which may occur on account of the great heatin the furnace-chamber.I propose, however, to provide a free and direct exit for the gases fromthe furnace-chamber and also provide space wherein they may expand, aswill hereinafter be fully described. As a result of this the temperaturein the top of the furnace will be greatly reduced, thus .lar shape,asishown.

not only saving the inner ends of the thimbles, but also the bell,hopper, and other parts of the furnace-top.

' The down-comer is connected to the gasport, and, as shown, it-firstproceeds upward as a substantially straight vertical pipe 15 to aconsiderable distance above the furnace-top and then makes an abruptbend and proceeds downward, as at 16, to the dust-collector. The thimble8 when arranged as in Fig. 1 must be oval in cross-section, as shown indotted lines, Fig. 3, in order to get the desired cross-area orcapacity, and the portion 15 of the down-comer starts at the bottom ofoval shape and then gradually'merges into circu- The down-comer at aconsiderable distance above the furnace-top, preferably at the bend atits upper end, is enlarged to form the expansion-chamber 17, in whichthe gases will expand, so as to facili tate the depositing of the fineores and coke carried up thereby. The bottom of this expansion-chamberis open and provided with a hopper or funnel 18, the lower end of whichis connected to the dust-pipe 19, which returns the ore and coke to thestack. To facilitate the depositing of the dust and ore into the hopper18, I preferably divide the expansion-chamber by the baffle-plate 20,which is cut away at its top, as at 21, to allow the gases to pass over,but which is in the path of the gases, so that the fine ores and cokewill strike against the same and be knocked down and deposited in thefunnel 18. To further aid this depositing of the fine ores and coke, Imay employ suitable blast apparatus, such as the steam or air pipes 22,of a suitable number and arranged on either one or both sides of thebaffle-plate, as shown, and which serve to direct the gases, with thesuspended ores and coke, against the baffle-plate 20 to be therebydeposited into the funnel 18. The dust-pipe 19 leads downward to thestack and may be connected to the same at any convenient place; but Ihave shown the same as leading to the hopper 5, so that the collectedores and coke are deposited in the hopper and are returned to thefurnace-chamber with the next charge of ore. This pipe is preferablyprovided with valves 23, 24, and 25, which are pivoted to the pipe andcounterbalanced by suitable weights 26, so that they will open when asufficient weight of ore and coke has been deposited on the same andwill then automatically return to their closed position. The ores andcoke may also be moistened, if desired, to prevent them from scatteringor flying about. Any suitable means maybe used for this purpose, such asthe spray-nozzles 27, projecting into the funnel 18 or other place.

At the upper end of the pipe 15 is the usual explosion-valve 28, whichmay be of any approved form.

The down-comer is preferably lined with fire-resisting material 29.

The number of gas-ports and down-comers may be varied, as desired ornecessary. For instance, in Fig. 1 I have shown two such gas-ports anddown-comers, while in Fig. 4 only one is shown; but the cross-sectionalarea of the latter is larger in proportion to the size of thefurnace-chamber than in Fig. 1 in order to give it the desired capacityfor carrying off the gases. In Fig. 4 also the thimble 8 is not oval,and as a consequence the entire length of the pipe 15 is circular incrosssection.

In Fig. 5 the furnace is shown as provided with a globe or dome-shapedtop 30, through which the gas-port 7 passes. The thimble 8 is omitted,and the furnace is shown provided with automatic feeding means 31 abovethe hopper. The pipe 15in this figure is connected to the portion 16 ofthe down-comer by the inclined pipe 32 and without any specificenlargement thereof to form an expansion-chamber. The dust-pipe 19 isalso omitted.

The furnace will be operated in the usual way, receiving at intervalsthe proper charge of ores, coke, &c., and the gases will pass throughthe gas-port 7 and down-comers in the usual way and of course will carrywith them more or less of the fine ores and coke. By reason, however, ofthe said down-comer rising in a substantially vertical direction to aconsiderable height above the top of the furnace the heavier and largerparticles of said ores and coke will naturally drop back into thefurnace-chamber, and it is upon this fact that the form shown in Fig. 5depends for its efficiency. Such portions, however, as are not depositedin the straight pipe 15 will pass with the gases into theexpansion-chamber 17, where said gases will expand and decrease invelocity, so that the ores and coke will fallinto the hopper 18. Theirdeposit is facilitated by striking against the baffle-plate 20, and thedeposit may be still further facilitated by the blast 22 driving thegases, with the ore and coke, against the baffle-plate. In the hopper 18the fine ores and coke are moistened by the spray 27, and when asufficient weight of said ores has been deposited in the hopper thevalves 23 will automatically open, allowing the deposit to fall downinto the dust-pipe 19 and if sufficient weight has accumulated to openthe valves 24 and 25 and drop into the hopper 5, whence they will bereturned to the stack with the next charge. Only a very inconsiderablequantity, if any, of the lightest dust will reach the downtake 16; butthis cannot clog the down-comer for the reason that the latter makes theabrupt bend, so that the dust which is carried over will fall down thedowntake. In case of an explosion in the furnace-chamber the gases willhave a practically straight unobstructed passage from said chamberupward through the pipe 15 to the explosion-valve 28, and, furthermore,the pipes 15 and the expansionchamber 17 provide a space in which theexploding gases can expand. As a result the furnace-top, hopper, andbell will be relieved of a great amount of pressure due to theexplosion.

What I claim as my invention, and desire to secure by Letters Patent, is

1. A blast-furnace having a shaft and top provided with a gas-portleading from the furnace chamber, a down-comer connected to saidgas-port, said down-comer projecting upwardly and extending above thefurnace-top to a considerable distance and then leading downwardly, anda dust-pipe connected to said down-comer above the furnace-top andleading back to the stack.

2. A blast-furnace having a shaft and top provided with a gasportleading from the furnace chamber, a down-comer connected to saidgas-port, said down-comer projecting upwardly and extending above thefurnace-top to a considerable distance and then leading downwardly andbeing enlarged above the furnace-top to form an expansion-chamber, and adust-pipe leading from the expansionchamber back to the stack.

3. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer projectingupwardly and extending above the furnace-top to a considerable distanceand then leading downwardly, a dust-catcher in said do wn-comer abovethe furnace-top, and a dust-pipe connected to the dust-catcher andleading back to the stack.

4. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer projectingupwardly and extending above the furnace-top to a considerable distanceand then making a sharp bend and leading downwardly, a funnel formed inthe bottom of said bend, and a dust-pipe leading from said funnel backto the stack.

5. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer being enlarged toform an expansion-chamber, a transverse baffle-plate in said expansionchamber, and a conduit connected to said expansion-chamber at the lowerend of said baffle-plate and leading back to the stack.

6. A blast-furnace having a shaft and top provided with a gas-port, adown-comer con nected to said gas-port, said down-comer pro jectingupwardly and extending above the furnace-top to a considerable distanceand being enlarged above the furnace-top to form an expansion-chamber, atransverse baffle plate in said expansion-chamber, and a dustpipeconnected to said expansion-chamber at the lower end of said bathe-plateand leading back to the stack.

7. A blast-furnace having a shaft and top provided with a gas-port, adown-comer con nected to said gas-port, said down-comer pro jectingupwardly and extending above the furnace-top to a considerable distanceand then making a sharp bend and leading downwardly, a funnel formed inthe bottom of said bend, a transverse bafiie-plate in said bend andprojecting downwardly into the funnel, and a dust-pipe leading from saidfunnel back to the stack.

8. A blast-furnace having a shaft and top provided with a gas-portleading from the furnace chamber, a. down-comer connected to saidgas-port, said down-comer projecting upwardly and extending above thefurnace-top to a considerable distance and then leading downwardly andbeing enlarged to provide an expansion-chamber, a dust-pipe leading fromsaid expansionchamber back to the stack, a transverse baffle-plate insaid expansion-chamber, and a blast pipe or pipes projecting inwardlyinto the chamber and directed toward the baffle-plate.

9. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer proj'ect-ingupwardly and extending above the fur nace-top to a considerable distanceand then leading downwardly, a dust-pipe connected to said down-comerabove the furnace-top and leading back to the stack, and valves in saiddust-pipe.

10. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer proj ectingupwardly and extending above the furnace-top to a considerable distanceand then leading downwardly, a dust-pipe connected to said down-comerabove the furnace and leading back to the stack, and a spray-pipe formoisteuing the dust in said pipe.

11. A blast-furnace having a shaft and top provided with a gas-port, adown-comer connected to said gas-port, said down-comer projectingupwardly and extending above the furnace-top to a considerable distanceand then making asharpbend and leading downwardly, afunnel in the lowerside of said bend, a dustpipe connected to the funnel and leading backto the stack, and a spray-nozzle projecting into said funnel.

' 12. A blast-furnace having a shaft and top nected to said pipe, and adust-pipe leading from the expansion-chamber back to the furnace-top.

13. A blast-furnace having a masonry shaft, a feeding-hopper and bell inthe top thereof, a gas-port extending through the masonry shaft with itsinner end in position to receive the.

discharge of ore from the hopper, and a castmetal thimble in saidgas-port with its inner end projecting to the furnace-chamber,wherebythe discharge of ore is prevented from wearing away the masonry.

14. Ablast-furnace havingamasonry shaft, a cast-metal thimble embeddedin the masonry at the top of the shaft to form a down-comer, saidthimble having its inner end provided with a cored-out flange, and waterconnections thereto to cool the same.

15. Ablast-furn'ace havingamasonry shaft, a thimble embedded in themasonry at the top of the shaft, brackets supported by the shaft andconnected to the thimble to support the same, and a down-comer connectedto said thimble.

l6. Ablast-furnace havingamasonry shaft, a thimble embedded in themasonry at the top of the shaft and leading from the furnacechamber outat the top of the shaft, brackets supported by the shaft and engagingshoulders on the thimble to support the same, said thimble being alsoprovided with shoulders to support the hopper-ring, and a down-comerconnected to said thimble.

In testimony whereof I, the said PATRICK MEEHAN, have hereunto set myhand.

PATRICK MEEHAN.

Witnesses:

F. W. WINTER, ROBERT C. TQTTEN.

